无法将 for 循环增量分配给 int 变量

Question

I'm writing a program that takes the highest/lowest values from 2 lists and records them, as well as at which for loop increment they've appeared.

This is the part of my code that is causing the problem. All variables you see here were declared earlier:

for(int i = 0; i < days; i++){
    highest_temp = high_temp[i];
    lowest_temp = low_temp[i];

    while (high_temp[i] > highest_temp){
        highest_temp = high_temp[i];
        highest_temp_day = i+1;
    }

    while  (low_temp[i] < lowest_temp){
        lowest_temp = low_temp[i];
        lowest_temp_day = i+1;
    }
}

printf("\n\nThe highest temperature was %d, on day %d", highest_temp, highest_temp_day);
printf("\nThe lowest temperature was %d on day %d", lowest_temp, lowest_temp_day);

This is my output:

The highest temperature was 9, on day 0
The lowest temperature was -4 on day 0

The variables highest_temp_day and lowest_temp_day were both initialied to 0 but they're not updated inside the while loops.

Answer 1

Your code needs to be restructured:

// these need to be outside so they don't get redefined constantly
int highest_temp = high_temp[0];
int lowest_temp = low_temp[0];
// initialize these to the first day
int highest_temp_day = 0;
int lowest_temp_day = 0;
// iterate through the array
for (int i = 0; i < days; i++) {
    // change whiles to ifs
    if (high_temp[i] > highest_temp) {
        // update vars
        highest_temp = high_temp[i];
        highest_temp_day = i + 1;
    }
    if (low_temp[i] < lowest_temp) {
        lowest_temp = low_temp[i];
        lowest_temp_day = i + 1;
    }
}

printf("\n\nThe highest temperature was %d, on day %d", highest_temp, highest_temp_day);
printf("\nThe lowest temperature was %d on day %d", lowest_temp, lowest_temp_day);